Melissa Cregger is a Staff Scientist in the Biosciences division at Oak Ridge National Laboratory. Dr. Cregger is an ecologist broadly interested in understanding microbial community dynamics across ecosystems, and how changes in microbial community structure may influence ecosystem level processes. Specifically, she is interested in understanding the potential for changes in microbial diversity and composition to influence large scale nutrient fluxes and the health of associated host organisms, both plant and mammalian. Her research spans scales from the molecule to the ecosystem level, taking advantage of modern techniques to fully understand microbial interactions. Dr. Cregger received her Ph.D. in Ecology and Evolutionary Biology in 2012 at the University of Tennessee under the guidance of Dr. Aimee Classen. After her Ph.D. she proceeded directly to a prestigious post-doctoral fellowship at the Carl Woese Institute for Genomic Biology at the University of Illinois in the Biocomplexity theme. There she expanded the focus of her work to examine host-microbe interactions in mammalian hosts. In 2014, she left the University of Illinois to begin a post-doctoral appointment with Dr. Chris Schadt at Oak Ridge National Laboratory. In 2015, she received a staff appointment at ORNL when she was awarded a Liane Russell Fellowship.